Sprinkler head



Nov. 19, 1929.

H. w. DOUGHTY 1,736,256

SPRINKLER HEAD Filed Dec. 192s INVENTOR HOWARD, WATERS oousu'n;

BY MQM M ATTORNEYS Application filed December 6, 1923. Serial No. 3249M.

This invention relates to fire extinguishing apparatus and particularly to sprinkler heads adapted to deliver extinguishing liquid automatically when a fire occurs in the 6 vicinity of one or more of the heads which are distributed about the premises to be protected.

Sprinkler heads as used heretofore comprise a body adapted to beconnected to a pipe 10 line or liquid receptacle and having an outlet through which the liquid is discharged. The outlet is sealed normally by a closure which is held in engagement therewith by a fusible link. When the temperature in the vicinity of a head rises to a predetermined point, the link fuses and the pressure of the liquid lifts the closure so that the liquid is permitted to escape in the formof a spray' and is distributed over the surrounding surface.

It sometimes happens that the closure does not tightlyeseal the outlet, and leakage may occur with resulting damage to material in the vicinity of the head. Moreover, in certain t pes of extinguishers, the pressure require to eject the liquid is developed by the heat resulting from the fire. In such extinguishers it is desirable that the closure should not be released prematurely.

It is the object of the present invention to provide an improved sprinkler head which afiords a tight seal for the liquid which, however, is released under appropriate conditions to permit the head to function.

A further object of the invention is the provision of a sprinkler head, the operation of which is subject to the dual control of temperature and the pressure of the liquid, so that the conditions under which the liquid is permitted to escape can be determined more accurately.

In carrying out the invention, I provide a sprinkler head difiering from the ordinary 45 type and including, for example, a base and an outlet nozzle threadedly connected to the base. An opening is provided in the base which is adapted to be connected to a pipe line or to a receptacle for liquid. A similar opening is provided in the nozzle, and the two openings register when the parts are assembled.

The base is formed with a shoulder surrounding the opening therein, and a correspondingshoulder is provided at the bottom of the nozzle. Between these shoulders I insert a diaphragm of frangible material preferably of metal foil such as aluminum foil, tin foil or the like. The thickness of the foil may-be determined with reference to the pressure at which it is intended to rupture, and the area which is exposed to the pressure. metal washers having openings therein reg- Preferabl the foil is mounted between two istering with the openings in the base and the nozzle. The washers may be coated before assembling with a suitable luting material such as nitrocellulose paste or a mixture of glycerin and litharge to ensure a tight joint.

The opening in the nozzle may be threaded or provided with a suitable shoulder and is adapted to be filled with any suitable material which is fusible at the desired temperature, for example, about F. For this purpose melted wax, stearin, stearic acid or other organic compound havin melting point is suitable. The llin of fusi' ble material closes the opening in t re nozzle and resists rupture of the diaphragm by pressure of the liquid in the pipe line or receptacle so long as the temperature surrounding the sprinkler head is below the melting point of the wax or other material. The threads or the shoulder in the nozzle prevent escape of the wax or other material until it'is melted.

When the sprinkler head is assembled, the washers enclosing the foil diaphragm are firmly held between the shoulders on the base and nozzle, thus sealing the outlet. The

outlet is closed, moreover, by the filling of wax or like material. 1 Leakage cannot occur, therefore, and the liquid cannot escape until the temperature rises to a predetermined point. Normally the pressure in an ordinary system will be suficient to rupture the diahragm only when the fusible material in the nozzle is melted. In systems in which the pressure is developed by the heat of the fire,

the desired the liquid cannot escape until the temperature rises to a predetermined point.

In the operation of the device as described, upon the occurrence of a fire the fusible material in the nozzle is melted when a certain temperature is attained. The resistance to the rupture of the diaphragm is thus withdrawn and the pressure of the liquid in the system is permitted to rupture the diaphragm, thus releasing the liquid which escapes through the opening in the nozzle and is sprayed over the surrounding surface. In systems in which pressure is developed by heat, the liquid will not be released immediately when the fusible material in the nozzle is melted unless the temperature is high. enough to develop the required pressure. As soon as that temperature is attained, the pressure will rupture the diaphragm and the liquid will be sprayed over the surrounding surface.

The invention will be better understood by reference to the following specification and accompanying drawing, in which Fig. 1 is a sectional View of the sprinkler head, and

Fig. 2 is a View in perspective of the diaphragm and washers.

Referring to the drawing, 5 indicates a base having a threaded opening 6 therethrough whereby the base is assembled with a pipe or receptacle for liquid. The base is provided with a threaded flange 7 to receive the nozzle 8 having an opening 9 registering with the opening 6.

Two washers 10 and 11 are disposed between the shoulders 12 and 13 on the base and nozzle respectively and a diaphragm 14 of frangible material such as metal foil is disposed between the washers, each of which has a central opening 15. The foil and washers may be cemented together as'hereinbefore indicated.

The opening 9 in the nozzle is threaded at 16 and is filled with a fusible material of the character hereinbefore described, which is adapted to melt at a predetermined temperature. The lower end of this fusible plug rests upon the diaphragm'and affords resistance, therefore, to prevent rupture of the diaphragm so long as the fusible material is solid. As soon as the temperature rises to a predetermined point, the plug is melted and the resistance is thus removed. If sulfici nt pressure has developed behind the dia phragm, the latter is ruptured and the liquid is permitted to escape through the nozzle and is delivered on the surrounding surface to extinguish the fire.

The device as described afiords a simple and satisfactory sprinkler head which avoids the diflieulties met heretofore. The dual control of the release is particularly effective in preventing premature discharge of the liquid'in the system.

Various changes may be made in the details of construction and arrangement of the parts without departing from the invention or sacrificing any of the advantages thereof.

I claim:

1. In a sprinkler head for use in fire extinguishers in which the pressure normally maintained in the extinguisher is below the operating pressure, the combination of a base having an opening affording a passage for fluid from the extinguisher, a nozzle having an outlet, and means subject to dual control of temperature and fluid pressure including a frangible diaphragm and a' plug of fusible material in the nozzle outlet, said means preventing the escape of fluid through the opening in the base and nozzle outlet until the pressure in the extinguisher reaches a predetermined amount above that normally maintained and until said plug has fused.

2. In a sprinkler head for use in fire extinguishers in which the pressure normally maintained in the extinguisher is below the operating pressure, the combination of a base having an opening affording a passage for fluid from the extinguisher, a nozzle having an outlet, and means subject to dual con trol of temperature and fluid pressure including a frangible diaphragm and a plug of fusible waxy material in the nozzleoutlet, said'means preventing the escape of fluid through the opening in the base and nozzle outlet until the pressure in the extinguisher reaches a predetermined amount above that lfiornally maintained and until saidplug has use 3. In a sprinkler head for use in fire extinguishers in which the pressure normal y maintained in the extinguisher is below the operating pressure, the combination of a base having an opening affording a passage for fluid from the extinguisher, a nozzle having an outlet registering with the opening in the base, washers between the base and nozzle, a frangible diaphragm between said wasners providing a closure rupturable under a pressure of predetermined amount above that normally maintained in the extinguisher, and a plug of fusible material in the nozzle outlet to resist rupture of the diaphragm and escape of the fluid until the plug is fused.

In testimony whereof I aflix my signature.

HOWVARD WATERS DOUGHTY. I 

